Confusing scratches on my left-arm

Every day I wake up, I always get these three scratches on my hand. I researched a little bit and people said it has to do with iron deficiency. My mom and dad said the same thing. So I am just wondering, does anyone here ever waked up with scratches on their arm or have any explanation of how to avoid it?



P.S. No it wasn't my cats. They don't sleep with me.